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WATCH: A Canadian couple have been accused of espionage and are being detained by authorities in China. Jacques Bourbeau reports.

TORONTO – An expert in Canada-China relations is questioning the timing of the arrests of two Canadians in China for stealing military secrets.

Charles Burton, an associate professor of Canada-China relations at Brock University, says he hasn’t seen foreigners charged with crimes involving military secrets since China’s Cultural Revolution in the mid-1960s.

“This is completely unprecedented,” he said. “The idea that the charges against this couple also relate to defence research secrets is rather coincidental.”

Kevin and Julia Dawn Garratt have been accused of stealing military and intelligence information and were detained by Chinese officials Tuesday. The Garratts were originally from Vancouver, B.C., but have lived in China since the 1980s.

The couple run a popular cafe in Dandong, China called Peter’s Cafe, which serves western food and offers weekly English conversation classes. They also run the charity North Star Aid, a humanitarian aid organization that works in North Korea.

The official Xinhua News Agency said in a report late Monday the Garratts were being investigated by the state security bureau in China’s northeastern city of Dandong that borders North Korea.

Foreign Affairs said in a statement they are aware two Canadians have been detained in China and are offering consular assistance.

Burton believes the charges are “trumped up” and questions the logic of the allegations facing the couple.

“I find it very hard to imagine that this couple that has been residing in China for 30 years are in fact secret agents of a foreign power tasked to obtain very sensitive military information,” said Burton. “This sort of thing is usually done by military attaches of embassies, not by people pretending to be Christian missionaries and English teachers and cafe owners.”

The arrests follow an incident last week where Canada blamed Chinese hackers for infiltrating computers at the National Research Council, a claim that was denied by the Chinese Embassy in Ottawa.

In a statement, the federal government said the attack was detected by one of Canada’s spy agencies, the Communications Security Establishment, who confirmed the cyber attack.

It says the intrusion was traced to “a highly sophisticated Chinese state-sponsored actor.”

“One cannot help but think that it could be retaliation for (Prime Minister Stephen Harper)’s outing of the Chinese intelligence services with regard to the hacking of Canadian government computers,” said Burton.

In an interview with Global News, the Garratts’ son Simeon said he was shocked when he heard the allegations and also questioned the political motivations of the arrests.

“I was caught completely off-guard, and it just seems insane to me to be honest…they’ve only really been involved in things that have benefitted China as a whole,” said Simeon. “Politically I think there’s probably something going on. Foreign Affairs is taking this very seriously, and obviously the allegations are very intense. Nobody really knows exactly what is going on.”

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China is Canada’s second largest trading partner, next to the United States, and in 2012 the total Canada-China was just under $70 billion and $72.9 billion, according to Canadian government figures.

Burton says if the matter isn’t resolved, it could cast a pall over Canada’s relations with China, with Harper expected to attend the Asia Pacific Economic Conference summit in Beijing in November.